| Year | Count |
|---|---|
| 1963 | 5 |
| 1972 | 11 |
| 1972 | 10 |
| 1975 | 5 |
| 1984 | 6 |
| 1985 | 20 |
| 1986 | 10 |
| 1988 | 7 |
| 1990 | 14 |
| 1991 | 56 |
| 1992 | 197 |
| 1993 | 119 |
| 1994 | 125 |
| 1995 | 39 |
| 1996 | 40 |
| 1997 | 63 |
| 1998 | 78 |
| 1999 | 51 |
| 2000 | 50 |
| 2001 | 87 |
| 2002 | 54 |
| 2003 | 71 |
| 2004 | 34 |
| 2005 | 47 |
| 2006 | 46 |
| 2007 | 22 |
| 2008 | 52 |
| 2009 | 76 |
| 2010 | 65 |
| 2011 | 52 |
| 2012 | 36 |
| 2013 | 38 |
| 2014 | 42 |
| 2015 | 25 |
| 2016 | 42 |
| 2017 | 69 |
| 2018 | 26 |
| 2019 | 32 |
| 2020 | 16 |
| 2021 | 30 |
| 2022 | 10 |
| 2023 | 23 |
| 2024 | 12 |